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Solar Assisted Heat Pumps (SAHP) use solar irradiation to boost the evaporation temperature. The experimental setup used in this thesis was located in Shanghai in China and heats water for domestic purposes. The experimental rig were built for R22 refrigerant which is targeted for phase-out according to the Montreal Protocol. A simulation model of the test rig was made to compare R290 and R22. Propane is a natural refrigerant having none of the negative effects associated with R22.

Climate change and energy scarcity put higher requirements on the use of energy in the society today. Buildings are a major contributor to the energy use and much attention is placed on energy efficient solutions in building services. One promising technology is hydronic radiant heating systems (RHS), which use moderate temperature water that can be supplied efficiently by green energy sources such as heat pumps, solar collectors and district heating. However, complexity in design and operation often makes RHS less economically competitive to traditional heating systems. Proper design procedures and control strategies must be developed in order to make this an economic solution for the future. In this work a RHS installed at the Green Energy Laboratory (GEL) at the Shanghai Jiao Tong University (SJTU) is analyzed with the use of the simulation tool TRNSYS. A simulation model is built and validated against measurements from the actual system. The goal is to analyze the performance of the installed RHS for typical Chinese apartments in a Shanghai climate, with a focus on energy efficiency and thermal comfort. The heat source is assumed to be an air source heat pump. Simulations are performed for different control strategies, insulation levels, heat pump sizes and thermal storages. Results show that the installed RHS can supply the entire heat load for a typical building in Shanghai. It is shown that for colder climate a greater level of insulation is required, as the floor has a maximum heat output of about 50 W/m2 at a supply temperature of 45°C. On/off thermostat control of the flow to each zone is confirmed to be sufficient. A stable heat pump operation is achieved with a storage tank, as cycling time is increased. Simulations are performed on fan coil units (FCU) as an alternative heat emitting system and results show that total heat demand is reduced by 11 %. However, the heat pump performance is reduced due to higher supply temperatures and the total electricity consumptions for the two systems are similar. RHS is here affirmed as a good solution for Chinese residential buildings, but a more detailed analysis of thermal comfort and a financial analysis should be conducted to assess its market competitiveness.

This study looks at the use of façade integrated solar collectors in Norwegian buildings. One wall consisting of 0.25 m of timber framed insulation, and one wall consisting of 0.2 m insulation and 0.2 m concrete were tested. The U-value of both walls were 0.17 W/m2K. The solar collectors were mounted on these wall elements as a replacement of the external weather barrier. The investigations were conducted in TRNSYS and in a dynamic model describing the thermal performance of the façade integrated solar collectors, created at Shanghai Jiao Tong University. The complete solar collector system was designed according to recommended values from literature. A parametric study looking at the optimal design of the storage tank set point temperature, the ratio between the tank height and the diameter, the regulatory strategy, the flow rate, the water tank volume and the placement of the heat exchanger were conducted. Following was a heat pump installed in series with the solar collectors in the existing system. Different maximum evaporator inlet temperatures were tested to find the optimal system design. The initial results showed that the heavy solar wall performed better than the lightweight solar wall. During the winter days, the heavy solar wall lead to a substantial reduction in the negative transmission compared to the conventional heavy wall. During the summer days, both of the solar walls introduced a positive transmission contribution, which may lead to overheating the building. The contribution was lowest for the heavy solar wall. When installing 6.68 m2 collector area in the TEK-10 building with the heavy wall configuration, the annual negative transmission was reduced by 84 % through the wall area with the installed collectors. A positive transmission of 39 kWh annually was also introduced. The parametric study revealed that the best design for system performance was not necessarily the optimal design for transmission energy savings. Related to transmission, lowering the flow rate showed the highest energy saving, of 1.5 kWh/m2 annually. In maximizing the collector performance, changing the regulatory strategy of the system led to an annual energy saving of 1.05 kWh/m2 floor area. This was also the efficiency measure that led to the biggest energy saving when accounting for both transmission and collector performance. The use of a series connected heat pump further improved the system performance. A maximum evaporator inlet temperature of 15 °C led to the highest energy saving of 30 % compared to the system without the heat pump, when accounting for both transmission and collector performance.